EP3453071B1 - Plastic waveguide for the propagation of waves in the frequency range comprised between 1 ghz and 10 thz - Google Patents

Description

BACKGROUND OF THE INVENTION Field of the invention

The present invention relates to the field of plastic waveguides for the propagation of waves of frequencies between 1 GHz and 10 THz, and more particularly relates to an improved assembly for the propagation of waves comprising such a plastic waveguide.

It also relates to a wired or wireless communication link for the transmission of high-speed signals, which comprises such an assembly.

Technological background

Waves with frequencies between 1 GHz and 10 THz are non-ionizing radiations which can penetrate a wide range of non-conductive materials such as wood, plastic, ceramics or even paper.

Also, the latter offer new and vast opportunities in technical fields as varied as spectroscopy, physics, communications, imaging, medicine and biology, to name but a few.

Intense research has thus been carried out for several years to ensure the propagation of such waves because the waveguides available for guiding electromagnetic waves in other frequency ranges are not suitable. In particular, the existing waveguides are not suitable for guiding terahertz waves, the frequency of which is between 0.1 THz and 10 THz.

Plastic waveguides have thus been reported for the propagation of terahertz waves.

Although constituting a significant advance over other devices developed based on metal for guiding terahertz waves, which are complex and rigid, these plastic waveguides have drawbacks.

Indeed, we observe that if a part of the waves propagates well in the plastic waveguide, another part of the terahertz waves propagates outside it.

These plastic waveguides for the propagation of terahertz waves of the prior art are, therefore, extremely sensitive to external contacts, which can cause significant losses in signal strength.

By way of illustration, it is then not possible to rest such plastic waveguides on a table, nor to handle them.

To remedy these drawbacks, attempts have therefore been made to cover these plastic waveguides with a low permittivity dielectric material or to place them in a foam.

Low loss materials are also used so as not to increase losses through attenuation due to propagation.

However, this results in an increased manufacturing cost of these plastic waveguides for the propagation of terahertz waves, which are also more complex to produce.

In addition, the use of foam is a source of risks for the mechanical stability and reliability of such terahertz waveguides.

The size of the terahertz waveguides thus protected is also increased.

There is therefore a pressing need for an assembly for the propagation of terahertz waves, and more generally for the propagation of waves in the frequency range between 1 GHz and 10 THz, the original design of which overcomes the drawbacks of the 'prior art recalled above

" Dielectric coaxial waveguide ", Devorer et al., JOURNAL OF APPLIED PHYSICS, vol. 44, no. 10, October 1, 1973 (1973-10-01), pages 4488-4500 and US3703690A disclose plastic dielectric waveguides comprising a central core and a shell separate from the core, or the core and the shell have different permittivities. EP2958187A1 discloses a dielectric waveguide comprising a central core and a tube connected to the core with plastic dielectric supports, which can be made integrally with the tube.

Object of the invention

The present invention relates to an assembly for the propagation of waves of frequencies between 1 GHz and 10 THz, simple in its design and in its operating mode, reliable and economical while allowing high-speed data transfer.

Another object of the present invention is a wired or wireless communication link comprising such an assembly for the propagation of waves of frequencies between 1 GHz and 10 THz, said link being inexpensive, offering a wide bandwidth and a high degree of mechanical reliability.

Another object of the present invention is a device for receiving / transmitting electromagnetic waves in the frequency band between 1 GHz and 10 THz comprising such an assembly for the propagation of waves.

BRIEF DESCRIPTION OF THE INVENTION

To this end, the invention relates to an assembly for the propagation of waves of frequencies between 1 GHz and 10 THz.

1. (a) un guide d'ondes pour guider lesdites ondes, ce guide d'ondes étant réalisé dans une matière plastique, une partie desdites ondes se propageant à l'intérieur de ce guide d'ondes et une autre partie desdites ondes se propageant à l'extérieur de ce guide d'ondes, et
2. (b) une enveloppe protectrice qui entoure le guide d'ondes en délimitant un ou plusieurs espaces entre ce guide d'ondes et cette enveloppe, dans lequel ou lesquels les ondes se propageant à l'extérieur de ce guide d'ondes sont contenues, ladite enveloppe protectrice formant ainsi une barrière pour protéger ces dernières des perturbations externes à l'ensemble,
3. (c) ladite enveloppe protectrice étant en plastique et réalisée dans la même matière plastique que ledit guide d'ondes, et en ce que ledit ensemble est d'une seule pièce.

According to the invention, this assembly comprises:

1. (a) a waveguide for guiding said waves, this waveguide being made of a plastic material, a part of said waves propagating inside this waveguide and another part of said waves propagating at outside of this waveguide, and
2. (b) a protective envelope which surrounds the waveguide by delimiting one or more spaces between this waveguide and this envelope, in which or which the waves propagating outside this waveguide are contained, said protective envelope thus forming a barrier to protect the latter from disturbances external to the assembly,
3. (c) said protective envelope being of plastic and made of the same plastic material as said waveguide, and in that said assembly is in one piece.

Advantageously, it is thus observed that this protective envelope truly isolates from the outside the waves propagating inside the waveguide and outside the waveguide, and consequently makes it possible to minimize the impact of disturbances. exterior on them. By forming a barrier, this protective envelope also prevents access to the space or spaces in which the waves propagating outside the waveguide evolve. It is therefore possible to have one or more areas of contact of the assembly with the outside without significant loss of signal strength.

Preferably, this protective envelope, or sheath, is arranged concentrically with this waveguide.

• ledit espace est rempli, ou lesdits espaces sont remplis, d'un fluide gazeux tel que de l'air.

In various particular embodiments of this assembly for the propagation of waves, each having its particular advantages and capable of numerous possible technical combinations:

• said space is filled, or said spaces are filled, with a gaseous fluid such as air.

Alternatively, this space or these spaces are under vacuum.

Still alternatively, this space or these spaces can be filled with a dielectric material having a permittivity lower than the permittivity of said waveguide.

• cette enveloppe protectrice étant un élément tubulaire allongé, au moins l'épaisseur W dudit élément tubulaire est déterminée de manière à minimiser l'influence de ladite enveloppe protectrice sur les modes de propagation.

Purely by way of illustration, the dielectric material having a permittivity lower than the permittivity of said waveguide is a foam.

• this protective envelope being an elongated tubular element, at least the thickness W of said tubular element is determined so as to minimize the influence of said protective envelope on the modes of propagation.

Preferably, this protective envelope is thus configured not only to facilitate obtaining the assembly for the propagation of waves, but also to prevent the latter from disturbing the modes of propagation of the waves inside the guide. of waves.

• cette enveloppe protectrice présente une section transversale droite circulaire ou sensiblement circulaire.

By way of example, this elongated tubular element may have a square, rectangular, elliptical, ...

• this protective envelope has a straight circular or substantially circular cross section.

Advantageously, such a configuration of the protective envelope makes it possible to limit the contacts of the assembly with a flat surface and, consequently, limits external disturbances.

However, the shape of this cross section can also be chosen from the group comprising square, rectangular, elliptical, ...

• ledit guide d'ondes présente une section transversale carrée, rectangulaire ou en forme de croix.

More generally, the protective envelope could have a surface relief participating in the removal of external disturbances. For example, the periphery of the protective casing could have ribs or protrusions.

• said waveguide has a square, rectangular or cross-shaped cross section.

Said waveguide having a cross-section in the form of a cross, the latter may be solid or have one or more holes.

The implementation of a waveguide with a cross-section in the shape of a cross makes it possible to double the number of possible propagation modes compared to a waveguide with a rectangular section, while reducing interference phenomena, or cross-talk, to a minimum. This is obtained by virtue of the orthogonality of fields oscillating at the same frequency.

Such a configuration is particularly advantageous in the context of full duplex communication, that is to say communication without interference.

It is also very useful for improving throughput in one-way, half-duplex and full-duplex communication modes.

Advantageously, such a configuration makes it possible to improve the compactness of a communication system integrating such a device compared to fully multimode communication devices.

The presence of one or more holes makes it possible to lighten the assembly and reduce losses. This or these holes can be filled with a dielectric material having a permittivity lower than the permittivity of said waveguide, which then contributes to the rigidity of the assembly for the propagation of the waves.

• cette enveloppe protectrice étant en plastique, elle est réalisée dans la même matière plastique que ledit guide d'ondes.

Purely by way of illustration, this dielectric material having a permittivity lower than the permittivity of said waveguide is a foam.

• this protective envelope being made of plastic, it is made of the same plastic material as said waveguide.

Advantageously, the protective envelope and the waveguide are made of polytetrafluoroethene (PTFE - Teflon®).

More generally, the protective envelope and the waveguide are made of at least one material chosen from the group comprising polyurethane (PU), polytetrafluoroethene, polyethylene (PE), polypropylene (PP), polystyrene (PS) , polycarbonate (PC), Mylar (PET), plexiglass (PMMA), polyvinyl (PVC), polychlorides, polyvinyls, Nylon (PA), acrylonitrile butadiene styrene (ABS), polyactic acid (PLA) and combinations thereof .

This set for wave propagation is one piece. Not resulting from the assembly of initially separate elements, this assembly advantageously exhibits increased mechanical strength and stability to ensure the guidance of the waves in the frequency band between 1 GHz and 10 THz.

Advantageously, such an assembly can also be obtained by any conventional method for manufacturing plastic parts such as by extrusion or by injection molding, and is therefore easy to manufacture. Its manufacturing cost is also low.

• ledit guide d'ondes est un guide d'ondes de fuite dans lequel le guide d'ondes comporte une ou plusieurs irrégularités pour générer des ondes électromagnétiques.

In addition, since the waves propagating outside the waveguide are not transported by the protective envelope, since the latter surrounds the space in which they propagate, no critical manufacturing tolerance is required for it to be obtained.

• said waveguide is a leakage waveguide in which the waveguide has one or more irregularities to generate electromagnetic waves.

The nature and the positioning of these irregularities are checked. These irregularities can thus be periodic or aperiodic.

Preferably, said protective envelope also comprises one or more irregularities for generating electromagnetic waves.

By way of purely example, such an irregularity may consist of a local modification of the section of the protective casing.

Advantageously, the assembly for the propagation of waves can thus form a oriented antenna for wireless communications.

The present invention also relates to a communication link. According to the invention, this communication link comprises an assembly for the propagation of waves as described above.

Preferably, each end of said assembly is coupled to a link connector, so as to allow two items of equipment to be connected with said assembly.

This communication link intended to transmit signals can be wired or wireless.

For example, this set for the propagation of waves comprising a first and a second end, it is coupled at each of its ends to a link connector chosen from the group comprising a USB connector, an HDMI connector, a DisplayPort connector (DP ) and a Thunderbolt connector. As an alternative, and again for example, it may also be a connector allowing connection to on-board systems.

This link connector can be of the male or female type.

In the case of a wireless communication link, the ends of the wave propagation assembly can be coupled to wireless transmitter / receiver devices for transmitting or receiving wireless signals.

The present invention also relates to a device for receiving / transmitting electromagnetic waves in the frequency band between 1 GHz and 10 THz.

According to the invention, this device comprises an assembly for the propagation of waves as described above.

BRIEF DESCRIPTION OF THE DRAWINGS

• la Figure 1 montre de manière schématique un ensemble pour la propagation d'ondes selon un premier mode de réalisation de la présente invention;
• la Figure 2 est une vue en coupe transversale de l'ensemble de la Fig.1 ;
• la Figure 3 est une vue en coupe transversale d'un ensemble pour la propagation d'ondes selon un second mode de réalisation de la présente invention;
• la figure 4 montre de manière schématique les lignes de champ de l'ensemble de la Fig.1 en l'absence d'une perturbation extérieure appliquée à cet ensemble pour trois modes de propagation, respectivement notés A (1^er mode), B (2^e mode) et C (3^e mode) pour une fréquence de 80 GHz;
• la figure 5 illustre un test de robustesse de l'ensemble de la Fig.1 dans lequel deux blocs remplis d'une solution aqueuse viennent localement entourer la surface extérieure de l'enveloppe de protection de cet ensemble pour simuler l'effet d'une préhension manuelle de cet ensemble ;
• la Figure 6 montre la distribution spatiale calculée du champ électrique pour le premier mode de propagation pour une fréquence de 80 GHz, c'est-à-dire le premier mode de propagation dans la section rectangulaire placée le long de l'axe des ordonnées (axe y) pour l'ensemble de la Fig. 5 ;
• la Figure 7 montre la distribution spatiale calculée du champ électrique pour le deuxième mode de propagation pour une fréquence de 80 GHz, c'est-à-dire le premier mode de propagation dans la section rectangulaire placée le long de l'axe des abscisses (axe x) pour l'ensemble de la Fig. 5 ;
• la Figure 8 montre la distribution spatiale calculée du champ électrique pour le troisième mode de propagation pour une fréquence de 80 GHz, c'est-à-dire le second mode de propagation dans la section rectangulaire placée le long de l'axe des ordonnées (axe y) pour l'ensemble de la Fig. 5 ;

Other advantages, aims and particular characteristics of the present invention will emerge from the description which will follow, given for the purpose of explanation and in no way limiting, with reference to the appended drawings, in which:

• the Figure 1 schematically shows an assembly for the propagation of waves according to a first embodiment of the present invention;
• the Figure 2 is a cross-sectional view of the entire Fig. 1 ;
• the Figure 3 is a cross-sectional view of a wave propagation assembly according to a second embodiment of the present invention;
• the figure 4 schematically shows the field lines of the entire Fig. 1 in the absence of an external disturbance applied to this set for three propagation modes, respectively denoted A (1 ^st mode), B (2 ^nd mode) and C (3 ^rd mode) for a frequency of 80 GHz;
• the figure 5 illustrates a robustness test of the whole Fig. 1 in which two blocks filled with an aqueous solution come locally to surround the outer surface of the protective casing of this assembly to simulate the effect of manual gripping of this assembly;
• the Figure 6 shows the calculated spatial distribution of the electric field for the first mode of propagation for a frequency of 80 GHz, i.e. the first mode of propagation in the rectangular section placed along the y-axis (y-axis) for the whole Fig. 5 ;
• the Figure 7 shows the calculated spatial distribution of the electric field for the second mode of propagation for a frequency of 80 GHz, i.e. the first mode of propagation in the rectangular section placed along the x-axis (x-axis) for the whole Fig. 5 ;
• the Figure 8 shows the calculated spatial distribution of the electric field for the third mode of propagation for a frequency of 80 GHz, i.e. the second mode of propagation in the rectangular section placed along the y-axis (y-axis) for the whole Fig. 5 ;

DETAILED DESCRIPTION OF EMBODIMENT OF THE INVENTION

First of all, we note that the figures are not to scale.

The Figures 1 and 2 schematically represent an assembly 10 for the propagation of waves according to a particular embodiment of the present invention.

This assembly 10 comprises a waveguide 11 for guiding waves of frequencies between 1 GHz and 10 THz, which is made of a plastic material such as polytetrafluoroethene.

This waveguide 11 is here an elongated solid part having a straight cross-section in the shape of a cross, which advantageously makes it possible to double the number of propagation modes with respect to a waveguide with rectangular section. The wave propagation axis is the longitudinal axis of this elongated solid part.

This assembly 10 also comprises a protective envelope 12, or sheath, which surrounds this plastic waveguide 11 by delimiting several spaces 13 - 16. Each of these spaces 13-16 is here delimited on the one hand by the inner wall of the protective casing 12 and on the other hand by external surfaces of the waveguide 11 with a cross-shaped section.

These spaces 13-16 are filled with a gaseous fluid, here air.

In an alternative embodiment, these spaces could be filled with a material having a permittivity lower than that of the waveguide.

This protective envelope 12 is here made of the same plastic material as the plastic waveguide 11, the assembly 10 for the propagation of the waves being in one piece. This assembly is here obtained by an injection molding process.

Part of the waves propagate in this plastic waveguide 11 while another part of these waves propagate outside this waveguide 11 in the spaces 13-14 thus defined.

The waves propagating outside the plastic waveguide 11 are consequently contained in these spaces while being surrounded by the protective envelope 12, which thus forms a barrier protecting the latter from external disturbances.

For a frequency of 80 GHz, this protective envelope 12 here has a thickness W of the order of 0.5 mm sufficient to effectively protect from external stresses, the waves propagating outside the waveguide 11.

In general, this envelope is defined so as to be on the one hand sufficiently thick to protect the waves propagating in spaces and the waves propagating inside the waveguide from external disturbances, and on the other hand not too thick so as not to transform the envelope itself into a propagation medium for waves which would disturb the operation of the waveguide.

The definition of this thickness results from a compromise which strongly depends on the frequency of the waves and the material used.

The Figure 3 shows an assembly 20 for the propagation of waves according to a second embodiment of the present invention.

The elements of the Fig. 3 bearing the same references as those of Figures 1 and 2 represent the same objects, which will not be described again below.

This assembly 20 for the propagation of waves comprises a waveguide 21 for guiding waves of frequencies between 1 GHz and 10 THz.

This waveguide 21 is here an elongated solid part having a straight cross section in the shape of a cross provided with a central hole 22. This configuration advantageously makes it possible to increase the number of propagation modes and to minimize losses.

The figure 4 shows the calculated spatial distribution of the electric field for the first three modes of propagation for a frequency of 80 GHz and for set 10 for the wave propagation described in Figures 1 and 2 in the absence of external disturbance applied to the assembly.

The figure 5 illustrates a robustness test of the assembly 10 for the wave propagation of the Fig. 1 , in which two blocks 30, 31 filled with an aqueous solution locally surround the outer surface of the protective casing 12 in order to simulate the effect of a manual gripping of the latter.

The elements of the Fig. 5 bearing the same references as those of Figures 1 and 2 represent the same objects, which will not be described again below.

These dielectric blocks 30, 31 have an electrical permittivity of eighty (80), which constitutes a major disturbance for the propagation of the waves in said assembly 10 for the propagation of waves.

The Figures 6 to 8 show the calculated spatial distribution of the electric field for the first three propagation modes for a frequency of 80 GHz and for set 10 for the wave propagation described in Figures 1 and 2 , when an external contact is applied to this assembly via the two blocks 30, 31 of dielectrics. These results were obtained from simulation software from ANSYS Inc., Canonsburg, PA 15317 USA.

They clearly show the advantage provided by the assembly for the propagation of waves of the present invention. Indeed, a comparison between the field lines generated in the set for the wave propagation of the Figure 4 and the field lines generated in the assembly for the wave propagation in the presence of an external disturbance, as shown in the Figures 6 to 8 , shows that the presence of blocks 30, 31 modifies the field lines in an insignificant manner.

The table below makes it possible to illustrate quantitatively the performances of the assembly for the propagation of waves of the invention.

The signal transmission is calculated on the one hand for an assembly comprising a cross-section waveguide of the Figure 1 for the first two modes of propagation, and on the other hand for a single waveguide of rectangular section. This transmission is calculated in the presence of blocks 30, 31 and in the absence of these blocks 30, 31. The assembly and the waveguide of rectangular section have a longitudinal dimension L of the order of 15 mm according to the Z axis. The protective casing has a thickness W of 0.5 mm. <u> Table </u> Transmission in the absence of blocks 30.31 Transmission in the presence of blocks 30.31 Additional losses Dimension (e) of each block along the z axis Set with cross-section waveguide [1 ^st mode] -0.09 dB -0.25 dB <0.2 dB 2.5mm Together with cross-shaped section waveguide ^[2nd Mode] -0.09 dB -0.25 dB <0.2 dB 2.5mm Rectangular section waveguide -0.09 dB -11.1 dB 11 dB 1.25 mm

This table clearly shows the low signal losses obtained for the assembly for the wave propagation of the invention, if we compare the results obtained with those of the waveguide which is not surrounded by a protective envelope. .

The losses due to the presence of blocks 30, 31 are calculated as being only of the order of a few tenths of decibels (dB).

The present invention thus makes it possible to obtain an assembly for the propagation of resistant and reliable waves at a particularly economical cost.

This assembly can be integrated into on-board electronics systems or in data processing centers to replace existing data transmission cables such as copper or fiber optic cables.

Claims (10)

1. An assembly for the propagation of waves of frequencies between 1 GHz and 10 THz, characterized in that it comprises:

   (a) a waveguide (11, 21) configured to guide said waves, said waveguide (11, 21) being produced from a plastic material, a part of said waves propagating inside said waveguide (11, 21) and another part of said waves propagating outside said waveguide (11, 21), and

   (b) a protective covering (12) which surrounds said waveguide (11, 21) delimiting one or more spaces (13-16) between said waveguide (11, 21) and said covering, in which space or spaces the waves propagating outside said waveguide (11, 21) are contained, said protective covering (12) configured to form thus a barrier to protect these waves from disturbances external to the assembly,

   (c) said protective covering (12) being made of plastic and produced from the same plastic material as said waveguide (11, 21), and wherein said assembly is of a single piece.
2. The assembly as claimed in claim 1, characterized in that said space is filled, or said spaces (13-16) are filled, with a gaseous fluid.
3. The assembly as claimed in claim 1, characterized in that said space is filled, or said spaces (13-16) are filled, with a material having a permittivity lower than that of said waveguide (11, 21).
4. The assembly as claimed in any one of claims 1 to 3, characterized in that said protective covering (12) exhibits a circular or substantially circular transverse cross-section.
5. The assembly as claimed in any one of claims 1 to 4, characterized in that said waveguide (11, 21) exhibits a square, rectangular or cross-shaped transverse cross-section, which is solid or includes one or more holes.
6. The assembly as claimed in claim 5, characterized in that said protective covering (12) and said waveguide (11, 21) are produced from at least one material chosen from the group comprising polyurethane, PU, polytetrafluoroethylene, polyethylene, PE, polypropylene, PP, polystyrene, PS, polycarbonate, PC, Polytéréphtalate d'ethylene, PET, polymethacrylate de methyl, PMMA, polyvinyl, PVC, polychlorides, polyvinyls, Nylon, PA, acrylonitrile butadiene styrene, ABS, polylactic acid, PLA and combinations of these elements.
7. The assembly as claimed in any one of claims 1 to 6. characterized in that said waveguide (11, 21) is a waveguide including one or more irregularities to generate electromagnetic waves.
8. The assembly as claimed in claim 7, characterized in that said protective covering (12) includes one or more irregularities to generate electromagnetic waves.
9. A communication link, characterized in that it includes an assembly for the propagation of waves as claimed in any one of claims 1 to 8, each of the ends of said assembly being coupled to a link connector, so as to enable two items of equipment to be connected to said assembly.
10. A device for receiving/transmitting electromagnetic waves in the band of frequencies between 1 GHz and 10 THz, characterized in that it includes an assembly for the propagation of waves as claimed in any one of claims 1 to 8.

Images